Field Properties for a 4-GeV Microtron Sector Magnet

The central magnetic field uniformity and field edge shapes have been investigated for a 609 metric ton sector magnet designed for the 4 GeV Electron Microtron (GEM) at Argonne National Laboratory. The effect of a Purcell filter on the central field uniformity was studied using the 2D magnetostatic computer program, TRIM. The effects on the shape of the edge field were studied for various geometries of endguard, pole tip shim, shield plate, pole edge shape, and coil. Both 2D and 3D programs were used for these latter studies and all results showed that the proposed design would produce acceptable field qualities.